Post req.body is always empty object

Question

I'm using Typescript Fetch wrapper to do post and get requests and getting empty object on post(get works fine) (Before I used Vanilla Js and all worked fine) Nodejs:

const express = require('express');
const fs = require('fs');
const app = express();
app.use(function (req, res, next) {
 res.header('Access-Control-Allow-Origin', '*');
 res.header(
 'Access-Control-Allow-Headers',
 'Origin, X-Requested-With, Content-Type, Accept'
 );
 next();
});
app.use(express.json());
app.post('/login', (req, res) => {
 let isLogged = login(req.body);
 console.log(req.body);
 res.status(200).json(isLogged);
});

My Typescript fetch Wrapper:

async function fetchWrapper<T>(path: string, config: RequestInit): Promise<T> {
 const request = new Request(path, config);
 const response = await fetch(request);
 if (!response.ok) {
 throw new Error(
 `name: ${response.status}, message: ${response.statusText}`
 );
 }
 // return empty object
 return response.json().catch(() => ({}));
}
 
export async function post<T, U>(
 path: string,
 body: T,
 config?: RequestInit
): Promise<U> {
 const init = { method: 'post', body: JSON.stringify(body), ...config };
 return await fetchWrapper<U>(path, init);
}

my post request:

 const res = await fetch.post(`${url}/login`, {
 body: inputData,
 headers: { 'Content-Type': 'application/json' },
 });

input data is not empty

Answer 1

The problem here that you are using wrong Content-Type header value. express.json parses application/json content type, while you are sending application/x-www-form-urlencoded. The solution is either to change the content-type you are sending, or add another middleware like bodyparser to parse application/x-www-form-urlencoded body.

• Shakhzod Yokubov: I changed it but get same results(
• Ayzrian: What have you changed?
• Shakhzod Yokubov: 'application/json'. My mistake was that I didn't pass parameters for fetch.put correctly, so I changed the wrapper and all worked for me